A problem with prior art multi screen synchronization systems is that because most of them are so constructed as to achieve time synchronization among two or more control apparatus, to issue a time stamp to a drawing instruction, or to achieve synchronization among two or more control apparatus in terms of signal processing using a mechanism for achieving synchronization between them, such as GenLock, the structure of the whole system becomes complicated.
Patent reference 1 discloses a system in which each of two or more control apparatus which are disposed for two or more display screens outputs a screen-display signal on the basis of inputted display information, when processing display elements relevant to two or more screens adjacent to the screen thereof, transmits a timing signal indicating that each of two or more control apparatus has been ready to perform a display process of displaying data on the display screen thereof to other control apparatus adjacent thereto, and, when receiving a timing signal indicating that another control apparatus has been ready to perform a display process of displaying data on the display screen thereof from the control apparatus, outputs an updated screen display signal. However, patent reference 1 simply relates to a technology for transmitting a timing signal to other adjacent control apparatus in order to secure the continuity of display elements, but does not disclose any technology for simultaneously generating screen displays.
[Patent reference 1] JP,7-319434, A (see paragraph 0006)
The present invention is made in order to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a screen synchronous control apparatus which can secure a synchronous display among two or more display screens with a simple structure by using a periodical reference timing signal when displaying data on two or more display screens.